package com.platform.server.util;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class MD5Util {
		private static String ALGORITHM_MD5 = "MD5";

		public final static String MD5(String s) {
			char hexDigits[]={'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
			try {
				byte[] btInput = s.getBytes();
				// 获得MD5摘要算法的 MessageDigest 对象
				MessageDigest mdInst = MessageDigest.getInstance("MD5");
				// 使用指定的字节更新摘要
				mdInst.update(btInput);
				// 获得密文
				byte[] md = mdInst.digest();
				// 把密文转换成十六进制的字符串形式
				int j = md.length;
				char str[] = new char[j * 2];
				int k = 0;
				for (int i = 0; i < j; i++) {
					byte byte0 = md[i];
					str[k++] = hexDigits[byte0 >>> 4 & 0xf];
					str[k++] = hexDigits[byte0 & 0xf];
				}
				return new String(str);
			} catch (Exception e) {
				e.printStackTrace();
				return null;
			}
		}

		public static String getMD5(String srcTxt) throws NoSuchAlgorithmException,
				NullPointerException {
			if (srcTxt == null) {
				throw new NullPointerException("输入参数为 NULL!");
			}

			String result = "";

			MessageDigest digest = MessageDigest.getInstance(ALGORITHM_MD5);
			digest.update(srcTxt.getBytes());
			byte[] byteRes = digest.digest();

			int length = byteRes.length;

			for (int i = 0; i < length; ++i) {
				result = result + byteHEX(byteRes[i]);
			}

			return result;
		}

		private static String byteHEX(byte ib) {
			char[] DigitNormal = { '0', '1', '2', '3', '4', '5', '6', '7', '8',
					'9', 'a', 'b', 'c', 'd', 'e', 'f' };

			char[] ob = new char[2];

			ob[0] = DigitNormal[(ib >>> 4 & 0xF)];

			ob[1] = DigitNormal[(ib & 0xF)];

			return new String(ob);
		}

		public static String getMD5byBase64(String input) {
			String result = null;
			byte[] byteRes = (byte[]) null;
			try {
				MessageDigest digest = MessageDigest.getInstance(ALGORITHM_MD5);
				digest.update(input.getBytes());
				byteRes = digest.digest();
			} catch (NoSuchAlgorithmException ex) {
				System.err.println(ex.getMessage());
			}

			result = Base64.encode(byteRes);

			return result;
		}
}
